Lamp socket



June 2, 1942. D. J. Kl-:LMAN 2,284,745

` LA MP SOCKET Filed June 14, 1940 INVENTOR. DAVID J. KELMAN `BY K 2 g I f ATTORNEY.

Patented June Z, 1942 UNITED STATES "PATENT OFFICE i 2,284,745 A LAMP sooner Davia J. Kelman, New York,`N. Y.' Application Junell, 1940, Serial No.' 340,449 solaires. (c1,- iva-35's) This invention relatesto electriclight sockets and more particularly to sockets adapted for use in 4connection with a series of Christmas tree bulbs or otherdecorative lights orv bulbs.

k Essentially this invention relates to a means of in the socket casing to retain the threaded end of the light bulb or other attachment and at the` same time to provide an electrically .conductive button at the end of the casing insulated from the metallic threaded cylinder.

The casing itself was thus merely a container for the two connections and the two connections, especially in the metallic cylinder, were such that they mightlbe .used in other ways and with other types of containers or casings. l

This type .of construction has been utilized wherever it has been necessaryto connect anat'- tachment to an electrical circuitiby screwingV a plug thereinto. This type of .construction has been utilized not merely for heavier constructions and permanent constructions,`"but evenV for such temporaryyapparatus'as decorative lamp circuits and Christmas tree light strings.

trical connection to one pole of the lamp and for supporting the lamp. i l

Indeed, I have found `that a small metallic insert for establishing such a connectionmay be used, said insert having one 'or more projections thereon to engage Vthe threadof the lamp that is placed within the socket. Such metallic insert may well occupy less than twenty degrees of the interior circumference `of the socket dependingV upon the sizeof the socket. Such metallic insert will therefore be'much less expensive-to manufacture `than the fullyV cylindrical `metallic threaded container heretofore u sed, while at the Y same time it will providefor the electrical connection to the lamp and for. support of the lamp.

'is woundabout the rivet and encased Within the bent-overfflange thereof, `Vwhileon the inside of Y whichto mount the metallic strip carrying' the f the end -wallthe bent-over Vflangeof the rivet forms the end connection against which one of the terminals of the light bulb is pressed. Y

In the construction of a socket of my invention, 1- providefor a recess in thesocket within lprojections whichv are to engage the thread-s on AnA object of the presentinvention is to form a` simplified electrical socket wherein electrical j with light bulbs, a socket of simplified construcliY tion and inexpensive to manufacture,` wherein suchlight bulbs may be screwed in order to esta'bf lish' electrical .connection and in order to support 'thelightbuln Y Y Another important object of thepresent invention is the provision of simplified supporting and `circuit connecting means for-decorative lamps such as Christmas tree bulbs.

In my invention, I have found that it is unnecessary to provide a fully cylindrical -metallic'in-v ternal threaded container for establishing elec*- .V is screwed in.

the member to be screwed in. This recess is :such that the metallic-striprwill'lie substantiallyflush with the interior4 surface Yand only thel projec tions thereon extending .-into theinteriorof the socket `to engage the., threads of the plug which -By the utilization of the means of my invention, therefore, the socket when constructed or moldecl,isprovided with all of the support elements-for the metallic connections andfno other supporting elements-such as screws or rivets or VVsealing wax are necessary to complete the support. VThat is, as willA hereinafter be` pointed out, the metallic strip is of such form that when inserted within the socket it cooperates with the supporting elements of the socket to provide for 1 permanent engagement ofthe metallic strip withinthe socket while the v.other connection is riveted about a perforation in the end .wall of the socket.

The integral structure4 :thus formed -s vincapable of disarrangement either by the action of heat or of any other inuence and is permanently arranged to cooperate with any electrical apparatus which may be mounted therein.

The socket may be formed by a simple molding operation and it is no more expensive to form the socket in the specic form necessary for the construction of my invention than to form the existing conventional socket structure.

Accordingly, it is a further object of my invention to provide an integral socket unit having by its inherent formation, supporting structure for the electrical connections to any element which may be mounted therein, and further providing supporting structure for the metallic means which in turn cooperates to support-` the structure mounted therein.

Many other objects and uses of this invention Y the arrows. Y

` Figure 4 is a vcross--sectional view taken on line 4-4of Figure 2 looking in the direction of the arrows. v

Figurer 5 isa view in perspective of the supporting and connecting strip to be mounted within the socket Yof Figures 1 to 4.

Figure 6 is a View in perspective of rthe rivet to be inserted in the end wall of the socket of Figures 2 to 4.

Referring now to Figure 1, I have here shown a socket structure I0 within which an electric light bulb B is mounted, the said light bulb having been screwed into the socket in the normai way.-

Thesocket comprises a molded container or socket element II having an extruded outer surface 26. v Wires I4 and I5 of the electrical conduit W are connected to the socket in the manner'- shown in Figure 2. The socket and conwiresor conduit W may support the socket or may support-a series of sockets insimilar manner inV the fashion commonly Vutilized in connectionhwith the draping and supporting of Christmastreebulbs.

',Referring now` to the remaining figures, which show the various parts of theinternal construcsarily have the form shown in Figure 5. They may constitute projections of any shape or form which may be suitable for engagement with the recesses or threads of a screw shaped member.

The strip I2 of Figure 5 is mounted in the recess 21 (Figures 2, 3 and 4) contained within the projection 26, Figure 1. The socket container II, when it is molded, is formed with a protrusion 26 and the recess 21 integrally formed therein, said recess 21 being substantially of the same width as the distance between the flanges I1, I1 (Figure 5) of the metallic strip I2.

The metallic strip I2 is slid or forced into the recess from the bottom or back end of the unit and is placed in such a manner that the flanges I1, I1 engage against the sides of the recess while the front I6 lies substantially flush with the interior surface of the socket; the projections I8 projecting somewhat into the interior of the socket.

The supporting wings 20, 20 are wider than the opening at the bottom of the recess and hence prevent the metallic strip I2 from moving beyond a predetermined position into the recess. The projections I8, I8 are thus positively positioned in the recess by making the front surface I6 the proper length and by striking up the wings 28, 28 which prevent further movement into the recess.

The anges I1, I1 are of sufficiently tight t in the recess 21 to frictionally prevent withdrawal of the member from the socket or recess and in fact, the very fact of supporting the bump within the socket or even of screwing the bulb into the vsocket further'assists in positioning the elements I8, I8 at the greatest possible distance from the back end of the socket. That is, when the light bulb is screwed in after the bulb has reached its limit of travel, further rotation thereof results in a pulling of the projection I8 towards the mouth or opening of the socket.

The opening 2| may be provided in the end of the metallic strip I2 to assist in positioning the same in a loading machine and to assist in 54,51 withdrawing the same when that is necessary for replacement and repair should such occasion arise.

vIt should be noted therefore from an inspection of Figures 1 to 4 inclusive, that'the light nections are of such nature that the electrical BD bulb need 110i? have any Speal C0nf0rmation and the threads T thereof'may cooperate with the projections I8 whether one projection, two projections or more of such projections are used for the purpose of positioning the bulb within the 3351 socket and at the same time for establishing election of the srocket'structure Ill, I have shown in Figure Y5 a metallic strip member I2 having a front surface I6 and supporting` and positioning flanges I1, and additional supporting and positicning wings 20, 20. The front surface I6 has thereonv a plurality of bumps or projections I8 preferably two in number, with spaces I9 therebetween, the spaces I9 being preferably of a width equal to theA width of each bump I8.

, lFor purposes of the present invention, it may bepossible `to utilizev only one such bumpr or projection VI8, although two, three, four or more such bumps or projections may be used.' Where aplurality of such bumps are utilized, the spaces I9 therebetween should be approximately equal to the over-all width of the bumps tions I8..,

trical connection from the strip I2 to the threads T of the bulb.

One of the wires of the electrical conduit W, as for instance wire I4, may at Ida be secured in any suitable manner to the strip I2 for the purpose of establishing electrical connections to one through the opening 2| in the metal strip I2 to or projecterminal of the source of electrical current.

Where it is desirable or necessary or where the connection at 14a should for any reason be disregarded, then the wire Ill may be passed *The bumps or projections I8 need not necesi751 through the Opening in the bOtm Wall S0 that the ange 22` rests against the bottom wall. And

then thecylindrical portion 23 isstruck down or bent over upon the other side of the bottom Wall, thus encasing the edges, of the openingsor perforation within the flanges of the rivet.

VThe wire 25 which is an extension of the wire I is placed around the rivet in the manner shown in Figures 2, 3 andv 4 before the rivet is finally fastened Yin place. When the cylindrical portion 23 is struck down,`as at 24, to encase the edges of the perforationthenthe wire 25 (extended rorn the wire I 5) is permanently secured to the rivet I3 As will be seen, particularly in connection with Figure 2, the endcontact C of the bulb B, when the threads T. thereof are in engagement with Y the projections I8 and whenlthe bulb has been screwed finally into place is pressed against the flange 2d of the rivet and hence establishes electrical connection between theother terminalof the bulb and the other terminal of the current supply. l

Obviously, it will be clear that the rivet may be` inserted from either wall and the wire .ex-

tended from thewire I5 maybe placed around either the existing flange of the rivet or the pressed down flange of the rivet.

In order to prevent any possibility of shortcircuiting between any `strands which may become unravelled Vor which may be loosened from the rivet and the metallic'strip I2, a wall 29 (see especially V`Figure 3) is provided as an-integral extension or projection of the end Wall 2B. Any wires which may thusbecome unravelled from the strand I5Y at the rivet ange 22'wi1l tend to strike the Wall 29 and thus there will be an avoidance of any possible short-circuiting effect.

This wall 29 may be integrally molded with the bottom wall at the time the-"socket element is constructed, and hence utilizationof the wall 28 does not require any increased manufacturing operations. The rivet maybe inserted inthe opening se that Vthe ange 22 is within the container and the post 23 to be turned down is on the outsideto engage the wire. Or the reverse procedure as above described may be followed.

The vmanner in`which the insertion is made depends upon the manufacturing equipment utilized for effecting the connection.

Where desirable or necessary, it may be possible to provide a metallic insert in the end wall of any other type of form supported therein in any suitable manner for establishing contact 3 least one of s'aid bumps and one terminal of the source of current.

The actual thickness of the. projection or bump (whatever its shape may be) or the distance which it projects into `the interior of the housing may vary Withinreasonable limits. The bump should project into the housing so that'the diametric distance from the tip of `the bump to the other side of the housing is less than the greatest diameter taken at the .raised portions of the threads T of the member which is screwed in, while the shortest diameterbetween the tip of the bump and ,the opposite wall should not be less than the diameter at one of the depressions of the memfbers'screwed in.

Since elements which are to be screwed into the sockets are provided with a thread having a relatively great depth,'the tolerance'available is a very wide one. Furthermore, where the bumps or projections I8 are mounted on a metallicstrip Y,

I2`which itself is inherently .and necessarily resilient variations even. beyond the tolerancesV Iabove set forth may still not ,be sufcient to destroy the operability. Y v f, f

As will be noted,.the1endwall 28 is depressed beneath the edges of the cylinder-so that, if desired, a Wax lling may be placed in suclrdepression over the 4connections in order to prevent unskilled tampering therewith. However, by reason of the foregoing constructions, such wax or other plastic insulating lling while it may, inv certain instances, be desirable, is by normeans l necessary.

Various'other'types of constructions may obviously be used nor is this invention necessarily confined to the .particular form or mounting of the bumps or projections hereinabove described. Thus, in particular cases, such bumps or projections instead of being mounted along a single line `longitildinally withinV the socket may beso arranged that one 'set' of bumps or projections extend asshown and other set of such bumps or projections extends along the interior wall of f the socket substantially diametrically opposite to l the first set.

Such other set of bumps or iprojections may be mounted on their own individual strip or a U-shaped strip may be utilized for this purpose.

Various other formations and placement of the bumps or projections may be utilized either along a single longitudinal lineas herein described, or

with the contact C of the electric light bulb or any other apparatus which may be thus connected to theV socket. And any other suitable connecting means may be provided with the wire conduit. y

Likewise, in connection with the metallic strip I2 and the projections or bumps I8, any suitable form of such projection or bump I8 may be utilized and such projection or bump I8 may be supported` in any suitable manner within the container.

In certain cases it may be desirable to provide projections or bumps for support integrally molded with the container and to insert but one metallic projection or bump for the purpose of Veifecting electrical contact.

In suitable cases metallic projections or bumps of the type ldescribed in the `present application may be mounted in the wall of the socket or housing II, in any other suitable manner, provided electrical contactisestablished between at 'in various staggered positions `within the container. Y Y

By the foregoing invention, I have devised a socket means for supporting threaded electrical Elements, said socket means as has above been operations .with sockets or containers for more complicated electrical elements.

While I have particularly described my invention with `relation to Christmas tree ornamentation and support of Christmas tree bulbs, it will Ialso be obvious that the socket construction herein set forth may also be utilized 'for any suitable purpose including the support and lighting of larger electric light bulbs or the (establishment of electrical connection to any other electrical apparatus of any kind whatsoever.

Where the surface I 6 of the strip I2 is sufficiently wide and the bumps or projections I8 thereon extend circumferentially a substantial distance, the bumps or projections I 8 may be slanted in a suitable direction to prevent too tight a frictional interference with the screwing in of the apparatus.

But in the ordinary case, the strip is sumciently narrow so that the bumps or projections I8 need not be given any specic direction with respect to any threads of the apparatus that may be screwed in. Likewise, the bumps I8 may have a configuration such that they are not oriented in any particular direction as, for instance, Where the bumps or projections are more or less circular.

By reason of this fact, apparatus may be screwed into the socket no matter in Which direction the threads of the screw go. That is, whether the apparatus should be screwed from right to left, or left to right, the appropriate rotation of such apparatus will result in the screwing in of such apparatus in the socket.

Accordingly, the socket of my invention is a universal one, wherein the same socket may be utilized for the support of threaded apparatus no matter in which direction the threads thereof run. Y

Many other objects and uses of my invention will now be obvious to those skilled in the art. I prefer, therefore, to be limited not by the specific disclosure herein, but only by the appended claims.

I claim: v

1. An electrical socket for reception of a threaded element, said socket comprising a cylindrical member of insulating material having an open end, and an end wall opposite the open end, an opening in the end wall, and a metallic projection from the Wall of the cylinder, said projection being an integral projection of a Inetallic strip, a recess in the Wall of the socket parallel to the axis of the socket, said strip being mounted in the recess, longitudinal flanges on the strip positioning it laterally within the recess and wings on the strip positioning it longitudinally Within the recess, and means for establishing electrical connection to said strip, said recess going through the end wall, said wings being positioned against the outer side of said end wall, and a rivet secured at the edges of said opening encasing the edges thereof, and an electrical connection to said rivet comprising a wire, the end of said wire secured between a portion of said rivet and said end wall.

2. An electrical socket for reception of a threaded element, said socket comprising a cylindrical member of insulating material having an open end, and an end wall opposite the open end, an opening in the end Wall, and a metallic projection from the wall of the cylinder, said projection being an integral projection of a metallic strip, a recess in the Wall of the socket parallel to the axis of the socket, said strip being mounted in the recess, longitudinal flanges on the strip positioning it laterally Within the recess and wings on the strip positioning it longitudinally within the recess, and means for establishing electrical connection to the strip, said recess going through the end Wall, said Wings being positioned against the outer side of said end wall, and a rivet secured at the edges of said opening encasing the edges thereof, and an 'electrical connection to said rivet comprising a wire, the end of said wire secured between a portion of said rivet and said end wall, and a guard wall between thevportion of the strip extending beyond the end Wall and the rivet,

DAVID J. KELMAN. 

